/*-------------------------------------------------------------------------
 *
 * fe-exec.c--
 *    functions related to sending a query down to the backend
 *
 * Copyright (c) 1994, Regents of the University of California
 *
 *
 * IDENTIFICATION
 *    $Header: /usr/local/cvsroot/postgres95/src/libpq/fe-exec.c,v 1.28 1997/01/24 17:47:33 scrappy Exp $
 *
 *-------------------------------------------------------------------------
 */
#include <stdlib.h>
#include <unistd.h>
#include <stdio.h>
#include <signal.h>
#include <string.h>
#include <errno.h>
#include "postgres.h"
#include "libpq/pqcomm.h"
#include "libpq/pqsignal.h"
#include "libpq-fe.h"
#include <sys/ioctl.h>
#ifndef HAVE_TERMIOS_H
# include <sys/termios.h>
#else
# include <termios.h>
#endif


#ifdef TIOCGWINSZ
struct winsize screen_size;
#else
struct winsize {
  int ws_row;
  int ws_col;
} screen_size;
#endif

/* the rows array in a PGresGroup  has to grow to accommodate the rows */
/* returned.  Each time, we grow by this much: */
#define TUPARR_GROW_BY 100

/* keep this in same order as ExecStatusType in pgtclCmds.h */
const char* pgresStatus[] = {
    "PGRES_EMPTY_QUERY",
    "PGRES_COMMAND_OK",
    "PGRES_TUPLES_OK",
    "PGRES_BAD_RESPONSE",
    "PGRES_NONFATAL_ERROR",
    "PGRES_FATAL_ERROR"
};


static PGresult* makePGresult(PGconn *conn, char *pname);
static void addTuple(PGresult *res, PGresAttValue *tup);
static PGresAttValue* getTuple(PGconn *conn, PGresult *res, int binary);
static PGresult* makeEmptyPGresult(PGconn *conn, ExecStatusType status);
static void fill(int length, int max, char filler, FILE *fp);

/*
 * PQclear -
 *    free's the memory associated with a PGresult
 *
 */
void
PQclear(PGresult* res)
{
    int i,j;

    if (!res)
        return;

    /* free all the rows */
    for (i=0;i<res->ntups;i++) {
        for (j=0;j<res->numAttributes;j++) {
            if (res->tuples[i][j].value)
                free(res->tuples[i][j].value);
        }
        free(res->tuples[i]);
    }
    free(res->tuples);

    /* free all the attributes */
    for (i=0;i<res->numAttributes;i++) {
        if (res->attDescs[i].name) 
            free(res->attDescs[i].name);
    }
    free(res->attDescs);
        
    /* free the structure itself */
    free(res);
}

/*
 * PGresult -
 *   returns a newly allocated, initialized PGresult
 *
 */

static PGresult*
makeEmptyPGresult(PGconn *conn, ExecStatusType status)
{
  PGresult *result;

  result = (PGresult*)malloc(sizeof(PGresult));

  result->conn = conn;
  result->ntups = 0;
  result->numAttributes = 0;
  result->attDescs = NULL;
  result->tuples = NULL;
  result->tupArrSize = 0;
  result->resultStatus = status;
  result->cmdStatus[0] = '\0';
  result->binary = 0;
  return result;
}

/*
 * getTuple -
 *   get the next row from the stream
 *
 *  the CALLER is responsible from freeing the PGresAttValue returned 
 */

static PGresAttValue*
getTuple(PGconn *conn, PGresult* result, int binary)
{
  char bitmap[MAX_FIELDS]; /* the backend sends us a bitmap of  */
                           /* which attributes are null */
  int bitmap_index = 0;
  int i;
  int nbytes;              /* the number of bytes in bitmap  */
  char  bmap;              /*  One byte of the bitmap */
  int   bitcnt = 0;        /* number of bits examined in current byte */
  int   vlen;              /* length of the current field value */
  FILE *pfin = conn->Pfin;
  FILE *pfdebug = conn->Pfdebug;

  PGresAttValue* tup;

  int nfields = result->numAttributes;

  result->binary = binary;

  tup = (PGresAttValue*) malloc(nfields * sizeof(PGresAttValue));

  nbytes = nfields / BYTELEN;
  if ( (nfields % BYTELEN) > 0)
    nbytes++;

  if (pqGetnchar(bitmap, nbytes, pfin, pfdebug) == 1){
      sprintf(conn->errorMessage,
              "Error reading null-values bitmap from row data stream\n");
      return NULL;
    }

  bmap = bitmap[bitmap_index];
  
  for (i=0;i<nfields;i++) {
    if (!(bmap & 0200)) {
        /* if the field value is absent, make it '\0' */
        tup[i].value = (char*)malloc(1);
        tup[i].value[0] = '\0';
        tup[i].len = NULL_LEN;
    }
    else {
      /* get the value length (the first four bytes are for length) */
      pqGetInt(&vlen, VARHDRSZ, pfin, pfdebug);
      if (binary == 0) {
        vlen = vlen - VARHDRSZ;
        }
      if (vlen < 0)
          vlen = 0;
      tup[i].len = vlen;
      tup[i].value = (char*) malloc(vlen + 1);
      /* read in the value; */
      if (vlen > 0)
          pqGetnchar((char*)(tup[i].value), vlen, pfin, pfdebug);
      tup[i].value[vlen] = '\0';
    }
    /* get the appropriate bitmap */
    bitcnt++;
    if (bitcnt == BYTELEN) {
      bitmap_index++;
      bmap = bitmap[bitmap_index];
      bitcnt = 0;
    } else
      bmap <<= 1;
  }

  return tup;
}


/*
 * addTuple
 *    add a row to the PGresult structure, growing it if necessary
 *  to accommodate
 *
 */
static void 
addTuple(PGresult* res, PGresAttValue* tup)
{
  if (res->ntups == res->tupArrSize) { 
    /* grow the array */
    res->tupArrSize += TUPARR_GROW_BY;
    
    if (res->ntups == 0)
      res->tuples = (PGresAttValue**) 
        malloc(res->tupArrSize * sizeof(PGresAttValue*));
    else
    /* we can use realloc because shallow copying of the structure is okay */
      res->tuples = (PGresAttValue**) 
        realloc(res->tuples, res->tupArrSize * sizeof(PGresAttValue*));
    }

  res->tuples[res->ntups] = tup;
  res->ntups++;
}

/*
 * PGresult
 *    fill out the PGresult structure with result rows from the backend
 *  this is called after query has been successfully run and we have
 *  a portal name
 *
 *  ASSUMPTION: we assume only *1* row group is returned from the backend
 *
 *  the CALLER is reponsible for free'ing the new PGresult allocated here
 *
 */

static PGresult*
makePGresult(PGconn* conn, char* pname)
{
  PGresult* result;
  int id;
  int nfields;
  int i;
  int done = 0;

  PGresAttValue* newTup;

  FILE* pfin = conn->Pfin;
  FILE* pfdebug = conn->Pfdebug;

  result = makeEmptyPGresult(conn, PGRES_TUPLES_OK);
  
  /* makePGresult() should only be called when the */
  /* id of the stream is 'T' to start with */

  /* the next two bytes are the number of fields  */
  if (pqGetInt(&nfields, 2, pfin, pfdebug) == 1) {
    sprintf(conn->errorMessage,
            "could not get the number of fields from the 'T' message\n");
    goto makePGresult_badResponse_return;
  }
  else
    result->numAttributes = nfields;

  /* allocate space for the attribute descriptors */
  if (nfields > 0) {
    result->attDescs = (PGresAttDesc*) malloc(nfields * sizeof(PGresAttDesc));
  }

  /* get type info */
  for (i=0;i<nfields;i++) {
    char typName[MAX_MESSAGE_LEN];
    int adtid;
    int adtsize;
    
    if ( pqGets(typName, MAX_MESSAGE_LEN, pfin, pfdebug) ||
        pqGetInt(&adtid, 4, pfin, pfdebug) ||
        pqGetInt(&adtsize, 2, pfin, pfdebug)) {
      sprintf(conn->errorMessage,
              "error reading type information from the 'T' message\n");
      goto makePGresult_badResponse_return;
    }
   result->attDescs[i].name = malloc(strlen(typName)+1);
   strcpy(result->attDescs[i].name,typName);
   result->attDescs[i].adtid = adtid;
   result->attDescs[i].adtsize = adtsize; /* casting from int to int2 here */
  }

  id = pqGetc(pfin,pfdebug);

  /* process the data stream until we're finished */
  while(!done) {
    switch (id) {
    case 'T': /* a new row group */
      sprintf(conn->errorMessage,
              "makePGresult() -- "
              "is not equipped to handle multiple row groups.\n");
      goto makePGresult_badResponse_return;
    case 'B': /* a row in binary format */
    case 'D': /* a row in ASCII format */
      newTup = getTuple(conn, result, (id == 'B'));
      if (newTup == NULL) 
        goto makePGresult_badResponse_return;
      addTuple(result,newTup);
      break;
    case 'C': /* end of portal row stream */
      {
      char command[MAX_MESSAGE_LEN];
      pqGets(command,MAX_MESSAGE_LEN, pfin, pfdebug); /* read command tag */
      done = 1;
    }
      break;
    case 'E': /* errors */
      if (pqGets(conn->errorMessage, ERROR_MSG_LENGTH, pfin, pfdebug) == 1) {
        sprintf(conn->errorMessage,
                "Error return detected from backend, "
                "but error message cannot be read");
      }
      result->resultStatus = PGRES_FATAL_ERROR;
      return result;
      break;
    case 'N': /* notices from the backend */
      if (pqGets(conn->errorMessage, ERROR_MSG_LENGTH, pfin, pfdebug) == 1) {
        sprintf(conn->errorMessage,
                "Notice return detected from backend, "
                "but error message cannot be read");
      } else
        /* XXXX send Notices to stderr for now */
        fprintf(stderr, "%s\n", conn->errorMessage);
      break;
    default: /* uh-oh
                this should never happen but frequently does when the 
                backend dumps core */
      sprintf(conn->errorMessage,
              "FATAL:  unrecognized data from the backend.  "
              "It probably dumped core.");
      fprintf(stderr, conn->errorMessage);
      result->resultStatus = PGRES_FATAL_ERROR;
      return result;
      break;
    }
    if (!done)
      id = getc(pfin);
  } /* while (1) */

  result->resultStatus = PGRES_TUPLES_OK;
  return result;

makePGresult_badResponse_return:
  result->resultStatus = PGRES_BAD_RESPONSE;
  return result;

}


/*
 * Assuming that we just sent a query to the backend, read the backend's 
 * response from stream <pfin> and respond accordingly.
 *
 * If <pfdebug> is non-null, write to that stream whatever we receive
 * (it's a debugging trace).
 * 
 * Return as <result> a pointer to a proper final PGresult structure,
 * newly allocated, for the query based on the response we get.  If the
 * response we get indicates that the query didn't execute, return a
 * null pointer and don't allocate any space, but also place a text
 * string explaining the problem at <*reason>.
 */

static void
process_response_from_backend(FILE *pfin, FILE *pfout, FILE *pfdebug, 
                              PGconn *conn, 
                              PGresult **result_p, char * const reason) {
  
  char id;
    /* The protocol character received from the backend.  The protocol
       character is the first character in the backend's response to our
       query.  It defines the nature of the response.
       */
  PGnotify *newNotify;
  bool done;  
    /* We're all done with the query and ready to return the result. */
  int emptiesSent;
    /* Number of empty queries we have sent in order to flush out multiple
       responses, less the number of corresponding responses we have 
       received.
       */
  int errors;
    /* If an error is received, we must still drain out the empty
       queries sent. So we need another flag.
       */
  char cmdStatus[MAX_MESSAGE_LEN];
  char pname[MAX_MESSAGE_LEN]; /* portal name */

  /* loop because multiple messages, especially NOTICES,
     can come back from the backend.  NOTICES are output directly to stderr
   */

  emptiesSent = 0;  /* No empty queries sent yet */
  errors = 0;       /* No errors received yet */
  pname[0] = '\0';

  done = false;  /* initial value */
  while (!done) {
    /* read the result id */
    id = pqGetc(pfin, pfdebug);
    if (id == EOF) {
      /* hmm,  no response from the backend-end, that's bad */
      (void) sprintf(reason,
                     "PQexec() -- Request was sent to backend, but backend "
                     "closed the channel before "
                     "responding.  This probably means the backend "
                     "terminated abnormally before or while processing "
                     "the request.\n");
      conn->status = CONNECTION_BAD;  /* No more connection to backend */
      *result_p = (PGresult*)NULL;
      done = true;
    } else {
      switch (id) {
      case 'A': 
        newNotify = (PGnotify*)malloc(sizeof(PGnotify));
        pqGetInt(&(newNotify->be_pid), 4, pfin, pfdebug);
        pqGets(newNotify->relname, NAMEDATALEN, pfin, pfdebug);
        DLAddTail(conn->notifyList, DLNewElem(newNotify));
        /* async messages are piggy'ed back on other messages,
           so we stay in the while loop for other messages */
        break;
      case 'C': /* portal query command, no rows returned */
        if (pqGets(cmdStatus, MAX_MESSAGE_LEN, pfin, pfdebug) == 1) {
          sprintf(reason,
                  "PQexec() -- query command completed, "
                  "but return message from backend cannot be read.");
          *result_p = (PGresult*)NULL;
          done = true;
        } else {
          /*
             // since backend may produce more than one result for some 
             // commands need to poll until clear 
             // send an empty query down, and keep reading out of the pipe
             // until an 'I' is received.
             */
          pqPuts("Q ", pfout, pfdebug); /* send an empty query */
          /*
           * Increment a flag and process messages in the usual way because
           * there may be async notifications pending.  DZ - 31-8-1996
           */
          emptiesSent++;
        }
        break;
      case 'E': /* error return */
        if (pqGets(conn->errorMessage, ERROR_MSG_LENGTH, pfin, pfdebug) == 1) {
          (void) sprintf(reason,
                         "PQexec() -- error return detected from backend, "
                         "but attempt to read the error message failed.");
        }
        *result_p = (PGresult*)NULL;
	errors++;
	if (emptiesSent == 0) {
	    done = true;
	}
        break;
      case 'I':  { /* empty query */
        /* read and throw away the closing '\0' */
        int c;
        if ((c = pqGetc(pfin,pfdebug)) != '\0') {
          fprintf(stderr,"error!, unexpected character %c following 'I'\n", c);
        }
        if (emptiesSent) {
          if (--emptiesSent == 0) { /* is this the last one? */
            /*
             * If this is the result of a portal query command set the
             * command status and message accordingly.  DZ - 31-8-1996
             */
	    if (!errors) {
		*result_p = makeEmptyPGresult(conn,PGRES_COMMAND_OK);
		strncpy((*result_p)->cmdStatus, cmdStatus, CMDSTATUS_LEN-1);
	    } else {
		*result_p = (PGresult*)NULL;
	    }
            done = true;
          }
        }
        else {
	  if (!errors) {
              *result_p = makeEmptyPGresult(conn, PGRES_EMPTY_QUERY);
	  } else {
	      *result_p = (PGresult*)NULL;
	  }
          done = true;
        }
      }
        break;
      case 'N': /* notices from the backend */
        if (pqGets(reason, ERROR_MSG_LENGTH, pfin, pfdebug) == 1) {
          sprintf(reason,
                  "PQexec() -- Notice detected from backend, "
                  "but attempt to read the notice failed.");
          *result_p = (PGresult*)NULL;
          done = true;
        } else
          /* Should we really be doing this?  These notices are not important
             enough for us to presume to put them on stderr.  Maybe the caller
             should decide whether to put them on stderr or not.  BJH 96.12.27
             */
          fprintf(stderr,"%s", reason);
        break;
      case 'P': /* synchronous (normal) portal */
        pqGets(pname, MAX_MESSAGE_LEN, pfin, pfdebug); /* read in portal name*/
        break;
      case 'T': /* actual row results: */
        *result_p = makePGresult(conn, pname);
        done = true;
        break;
      case 'D': /* copy command began successfully */
        *result_p = makeEmptyPGresult(conn, PGRES_COPY_IN);
        done = true;
        break;
      case 'B': /* copy command began successfully */
        *result_p = makeEmptyPGresult(conn, PGRES_COPY_OUT);
        done = true;
        break;
      default:
        sprintf(reason,
                "unknown protocol character '%c' read from backend.  "
                "(The protocol character is the first character the "
                "backend sends in response to a query it receives).\n",
                id);
        *result_p = (PGresult*)NULL;
        done = true;
      } /* switch on protocol character */
    } /* if character was received */
  } /* while not done */
}



/*
 * PQexec
 *    send a query to the backend and package up the result in a Pgresult
 *
 *  if the query failed, return NULL, conn->errorMessage is set to 
 * a relevant message
 *  if query is successful, a new PGresult is returned
 * the use is responsible for freeing that structure when done with it
 *
 */

PGresult*
PQexec(PGconn* conn, const char* query)
{
  PGresult *result;
  char buffer[MAX_MESSAGE_LEN];

  if (!conn) return NULL;
  if (!query) {
    sprintf(conn->errorMessage, "PQexec() -- query pointer is null.");
    return NULL;
  }

  /*clear the error string */
  conn->errorMessage[0] = '\0';

  /* check to see if the query string is too long */
  if (strlen(query) > MAX_MESSAGE_LEN) {
    sprintf(conn->errorMessage, "PQexec() -- query is too long.  "
            "Maximum length is %d\n", MAX_MESSAGE_LEN -2 );
    return NULL;
  }

  /* Don't try to send if we know there's no live connection. */
  if (conn->status != CONNECTION_OK) {
    sprintf(conn->errorMessage, "PQexec() -- There is no connection "
            "to the backend.\n");
    return NULL;
  }
  
  /* the frontend-backend protocol uses 'Q' to designate queries */
  sprintf(buffer,"Q%s",query);

  /* send the query to the backend; */
  if (pqPuts(buffer, conn->Pfout, conn->Pfdebug) == 1) {
      (void) sprintf(conn->errorMessage,
                     "PQexec() -- while sending query:  %s\n"
                     "-- fprintf to Pfout failed: errno=%d\n%s\n",
                     query, errno, strerror(errno));
      return NULL;
  }

  process_response_from_backend(conn->Pfin, conn->Pfout, conn->Pfdebug, conn,
                                &result, conn->errorMessage);
  return(result);
}



/*
 * PQnotifies
 *    returns a PGnotify* structure of the latest async notification
 * that has not yet been handled
 *
 * returns NULL, if there is currently 
 * no unhandled async notification from the backend
 *
 * the CALLER is responsible for FREE'ing the structure returned
 */

PGnotify*
PQnotifies(PGconn *conn)
{
    Dlelem *e;

    if (!conn) return NULL;

    if (conn->status != CONNECTION_OK) 
        return NULL;
    /* RemHead returns NULL if list is empy */
    e = DLRemHead(conn->notifyList);
    if (e) 
        return (PGnotify*)DLE_VAL(e);
    else 
        return NULL;
}

/*
 * PQgetline - gets a newline-terminated string from the backend.
 * 
 * Chiefly here so that applications can use "COPY <rel> to stdout"
 * and read the output string.  Returns a null-terminated string in s.
 *
 * PQgetline reads up to maxlen-1 characters (like fgets(3)) but strips
 * the terminating \n (like gets(3)).
 *
 * RETURNS:
 *      EOF if it is detected or invalid arguments are given
 *      0 if EOL is reached (i.e., \n has been read)
 *              (this is required for backward-compatibility -- this
 *               routine used to always return EOF or 0, assuming that
 *               the line ended within maxlen bytes.)
 *      1 in other cases
 */
int
PQgetline(PGconn *conn, char *s, int maxlen)
{
    int c = '\0';

    if (!conn) return EOF;
    
    if (!conn->Pfin || !s || maxlen <= 1)
        return(EOF);
    
    for (; maxlen > 1 && 
          (c = pqGetc(conn->Pfin, conn->Pfdebug)) != '\n' && 
           c != EOF;
         --maxlen) {
        *s++ = c;
    }
    *s = '\0';
    
    if (c == EOF) {
        return(EOF);            /* error -- reached EOF before \n */
    } else if (c == '\n') {
        return(0);              /* done with this line */
    }
    return(1);                  /* returning a full buffer */
}


/*
 * PQputline -- sends a string to the backend.
 * 
 * Chiefly here so that applications can use "COPY <rel> from stdin".
 *
 */
void
PQputline(PGconn *conn, const char *s)
{
    if (conn && (conn->Pfout)) {
        (void) fputs(s, conn->Pfout);
        fflush(conn->Pfout);
    }
}

/*
 * PQendcopy
 *      called while waiting for the backend to respond with success/failure
 *      to a "copy".
 *
 * RETURNS:
 *      0 on success
 *      1 on failure
 */
int
PQendcopy(PGconn *conn)
{
    FILE *pfin, *pfdebug;
    bool valid = true;

    if (!conn) return (int)NULL;

    pfin = conn->Pfin;
    pfdebug = conn->Pfdebug;

    if ( pqGetc(pfin,pfdebug) == 'C')
    {
      char command[MAX_MESSAGE_LEN];
      pqGets(command,MAX_MESSAGE_LEN, pfin, pfdebug); /* read command tag */
    }
    else valid = false;

    if ( valid )
	return (0);
    else {
        sprintf(conn->errorMessage,
                    "Error return detected from backend, "
                    "but attempt to read the message failed.");
        fprintf(stderr,"resetting connection\n");
        PQreset(conn);
        return(1);
    }
}

/* simply send out max-length number of filler characters to fp */
static void
fill (int length, int max, char filler, FILE *fp)
{
  int count;
  char filltmp[2];

  filltmp[0] = filler;
  filltmp[1] = 0;
  count = max - length;
  while (count-- >= 0)
    {
      fprintf(fp, "%s", filltmp);
    }
 }


/*
 * PQdisplayTuples()
 * kept for backward compatibility
 */
void
PQdisplayTuples(PGresult *res,
                FILE *fp,      /* where to send the output */
                int fillAlign, /* pad the fields with spaces */
                const char *fieldSep,  /* field separator */
                int printHeader, /* display headers? */
                int quiet
                )
{
#define DEFAULT_FIELD_SEP " "

    int i, j;
    int nFields;
    int nTuples;
    int fLength[MAX_FIELDS];

    if (fieldSep == NULL)
        fieldSep = DEFAULT_FIELD_SEP;

    /* Get some useful info about the results */
    nFields = PQnfields(res);
    nTuples = PQntuples(res);
  
    if (fp == NULL) 
        fp = stdout;

    /* Zero the initial field lengths */
    for (j=0  ; j < nFields; j++) {
      fLength[j] = strlen(PQfname(res,j));
    }
    /* Find the max length of each field in the result */
    /* will be somewhat time consuming for very large results */
    if (fillAlign) {
        for (i=0; i < nTuples; i++) {
            for (j=0  ; j < nFields; j++) {
                if (PQgetlength(res,i,j) > fLength[j])
                    fLength[j] = PQgetlength(res,i,j);
            }
        }
    }
    
    if (printHeader) {
        /* first, print out the attribute names */
        for (i=0; i < nFields; i++) {
            fputs(PQfname(res,i), fp);
            if (fillAlign)
                fill (strlen (PQfname(res,i)), fLength[i], ' ', fp);
            fputs(fieldSep,fp);
        }
        fprintf(fp, "\n");
  
        /* Underline the attribute names */
        for (i=0; i < nFields; i++) {
            if (fillAlign)
                fill (0, fLength[i], '-', fp);
            fputs(fieldSep,fp);
        }
        fprintf(fp, "\n");
    }

    /* next, print out the instances */
    for (i=0; i < nTuples; i++) {
      for (j=0  ; j < nFields; j++) {
        fprintf(fp, "%s", PQgetvalue(res,i,j));
        if (fillAlign)
            fill (strlen (PQgetvalue(res,i,j)), fLength[j], ' ', fp);
        fputs(fieldSep,fp);
      }
      fprintf(fp, "\n");
    }
  
    if (!quiet)
        fprintf (fp, "\nQuery returned %d row%s.\n",PQntuples(res),
                 (PQntuples(res) == 1) ? "" : "s");
  
    fflush(fp);
}



/*
 * PQprintTuples()
 *
 * kept for backward compatibility
 *
 */
void
PQprintTuples(PGresult *res,
              FILE* fout,      /* output stream */
              int PrintAttNames,/* print attribute names or not*/
              int TerseOutput, /* delimiter bars or not?*/
              int colWidth   /* width of column, if 0, use variable width */
              )
{
    int nFields; 
    int nTups;
    int i,j;
    char formatString[80];

    char *tborder = NULL;

    nFields = PQnfields(res);
    nTups = PQntuples(res);

    if (colWidth > 0) {
      sprintf(formatString,"%%s %%-%ds",colWidth);
    } else
      sprintf(formatString,"%%s %%s");

    if ( nFields > 0 ) {  /* only print rows with at least 1 field.  */

        if (!TerseOutput)
        {
            int width;
            width = nFields * 14;
            tborder = malloc (width+1);
            for (i = 0; i <= width; i++) 
                tborder[i] = '-';
            tborder[i] = '\0';
            fprintf(fout,"%s\n",tborder);
        }

        for (i=0; i < nFields; i++) {
            if (PrintAttNames) {
                fprintf(fout,formatString,
                        TerseOutput ? "" : "|",
                        PQfname(res, i));
            }
        }

        if (PrintAttNames) {
            if (TerseOutput)
                fprintf(fout,"\n");
            else
                fprintf(fout, "|\n%s\n",tborder);
        }
        
        for (i = 0; i < nTups; i++) {
            for (j = 0; j < nFields; j++) {
                char *pval = PQgetvalue(res,i,j);
                fprintf(fout, formatString,
                        TerseOutput ? "" : "|",
                        pval ? pval : "");
            }
            if (TerseOutput)
                fprintf(fout,"\n");
            else
                fprintf(fout, "|\n%s\n",tborder);
        }
    }
}



static void
do_field(PQprintOpt *po, PGresult *res, 
         const int i, const int j, char *buf, const int fs_len, 
         char *fields[], 
         const int nFields, char *fieldNames[],
         unsigned char fieldNotNum[], int fieldMax[], 
         const int fieldMaxLen, FILE *fout
         ) {

    char *pval, *p, *o;
    int plen;
    bool skipit;

    plen=PQgetlength(res,i,j);
    pval=PQgetvalue(res,i,j);

    if (plen < 1 || !pval || !*pval) {
        if (po->align || po->expanded) skipit = true;
        else {
            skipit = false;
            goto efield;
        }
    } else skipit = false;

    if (!skipit) {
        for (p=pval, o=buf; *p; *(o++)=*(p++)) {
            if ((fs_len==1 && (*p==*(po->fieldSep))) || *p=='\\')
              *(o++)='\\';
            if (po->align && (*pval=='E' || *pval=='e' ||
                              !((*p>='0' && *p<='9') || 
                                *p=='.' || 
                                *p=='E' || 
                                *p=='e' || 
                                *p==' ' || 
                                *p=='-')))
              fieldNotNum[j]=1;
        }
        *o='\0';
        if (!po->expanded && (po->align || po->html3)) {
            int n=strlen(buf);
            if (n>fieldMax[j])
              fieldMax[j]=n;
            if (!(fields[i*nFields+j]=(char *)malloc(n+1))) {
                perror("malloc");
                exit(1);
            }
            strcpy(fields[i*nFields+j], buf);
        } else {
            if (po->expanded) {
                if (po->html3)
                  fprintf(fout, 
                          "<tr><td align=left><b>%s</b></td>"
                          "<td align=%s>%s</td></tr>\n",
                          fieldNames[j], 
                          fieldNotNum[j] ? "left": "right", 
                          buf);
                else {
                    if (po->align)
                      fprintf(fout, 
                              "%-*s%s %s\n", 
                              fieldMaxLen-fs_len, fieldNames[j], po->fieldSep, 
                              buf);
                    else
                      fprintf(fout, "%s%s%s\n", fieldNames[j], po->fieldSep, buf);
                }
            } else {
                if (!po->html3) {
                    fputs(buf, fout);
                  efield:
                    if ((j+1)<nFields)
                      fputs(po->fieldSep, fout);
                    else
                      fputc('\n', fout);
                }
            }
        }
    }
}


static void
do_header(FILE *fout, PQprintOpt *po, const int nFields, int fieldMax[], 
          char *fieldNames[], unsigned char fieldNotNum[],
          const int fs_len, char *border, PGresult *res) {

    int j;   /* for loop index */

    if (po->html3)
      fputs("<tr>", fout);
    else {
        int j;  /* for loop index */
        int tot=0;
        int n=0;
        char *p;
        for (; n < nFields; n++)
          tot+=fieldMax[n]+fs_len+(po->standard? 2: 0);
        if (po->standard)
          tot+=fs_len*2+2;
        if (!(p=border=malloc(tot+1))) {
            perror("malloc");
            exit(1);
        }
        if (po->standard) {
            char *fs=po->fieldSep;
            while (*fs++)
              *p++='+';
        }
        for (j=0; j < nFields; j++) {
            int len;
            for (len=fieldMax[j] + (po->standard? 2:0) ; len--; *p++='-');
            if (po->standard || (j+1)<nFields) {
                char *fs=po->fieldSep;
                while (*fs++)
                  *p++='+';
            } 
        }
        *p='\0';
        if (po->standard)
          fprintf(fout, "%s\n", border);
    }
    if (po->standard)
      fputs(po->fieldSep, fout);
    for (j=0; j < nFields; j++) {
        char *s=PQfname(res, j);
        if (po->html3) {
            fprintf(fout, "<th align=%s>%s</th>", 
                    fieldNotNum[j]? "left": "right", fieldNames[j]);
        } else {
            int n=strlen(s);
            if (n>fieldMax[j])
              fieldMax[j]=n;
            if (po->standard)
              fprintf(fout, 
                      fieldNotNum[j] ? " %-*s ": " %*s ", 
                      fieldMax[j], s);
            else
              fprintf(fout, fieldNotNum[j] ? "%-*s": "%*s", fieldMax[j], s);
            if (po->standard || (j+1)<nFields)
              fputs(po->fieldSep, fout);
        }
    }
    if (po->html3)
      fputs("</tr>\n", fout);
    else
      fprintf(fout, "\n%s\n", border);
}


static void
output_row(FILE *fout, PQprintOpt *po, const int nFields, char *fields[], 
           unsigned char fieldNotNum[], int fieldMax[], char *border, 
           const int row_index) {

    int field_index;  /* for loop index */

    if (po->html3)
      fputs("<tr>", fout);
    else if (po->standard)
      fputs(po->fieldSep, fout);
    for (field_index = 0; field_index < nFields; field_index++) {
        char *p=fields[row_index*nFields+field_index];
        if (po->html3)
          fprintf(fout, "<td align=%s>%s</td>", 
                  fieldNotNum[field_index]? "left": "right", p? p: "");
        else {
            fprintf(fout, 
                    fieldNotNum[field_index] ? 
                        (po->standard ? " %-*s ": "%-*s") : 
                        (po->standard ? " %*s ": "%*s"), 
                    fieldMax[field_index], 
                    p ? p: "");
            if (po->standard || field_index+1 < nFields)
              fputs(po->fieldSep, fout);
        }
        if (p)
          free(p);
    }
    if (po->html3)
      fputs("</tr>", fout);
    else
      if (po->standard)
        fprintf(fout, "\n%s", border);
    fputc('\n', fout);
}




/*
 * PQprint()
 *
 * Format results of a query for printing.
 *
 * PQprintOpt is a typedef (structure) that containes
 * various flags and options. consult libpq-fe.h for
 * details
 *
 * Obsoletes PQprintTuples.
 */

void
PQprint(FILE *fout,
              PGresult *res,
              PQprintOpt *po
              )
{
    int nFields;

    nFields = PQnfields(res);

    if ( nFields > 0 ) {  /* only print rows with at least 1 field.  */
        int i,j;
        int nTups;
        int *fieldMax=NULL;     /* in case we don't use them */
        unsigned char *fieldNotNum=NULL;
        char *border=NULL;
        char **fields=NULL;
        char **fieldNames;
        int fieldMaxLen=0;
        int numFieldName;
        int fs_len=strlen(po->fieldSep);
        int total_line_length = 0;
        int usePipe = 0;
        char *pagerenv;
        char buf[8192*2+1];

        nTups = PQntuples(res);
        if (!(fieldNames=(char **)calloc(nFields, sizeof (char *)))) {
            perror("calloc");
            exit(1);
        }
        if (!(fieldNotNum=(unsigned char *)calloc(nFields, 1))) {
            perror("calloc");
            exit(1);
        }
        if (!(fieldMax=(int *)calloc(nFields, sizeof(int)))) {
            perror("calloc");
            exit(1);
        }
        for (numFieldName=0; 
             po->fieldName && po->fieldName[numFieldName]; 
             numFieldName++)
                ;
        for (j=0; j < nFields; j++) {
            int len;
            char *s = 
              (j<numFieldName && po->fieldName[j][0])? 
                po->fieldName[j]: PQfname(res, j);
            fieldNames[j]=s;
            len=s ? strlen(s): 0;
            fieldMax[j] = len;
            len+=fs_len;
            if (len>fieldMaxLen)
              fieldMaxLen=len;
            total_line_length += len;
        }
 
        total_line_length += nFields * strlen(po->fieldSep) + 1;
 
        if (fout == NULL) 
            fout = stdout;
        if (po->pager && fout == stdout &&
            isatty(fileno(stdin)) &&
            isatty(fileno(stdout))) {
            /* try to pipe to the pager program if possible */
#ifdef TIOCGWINSZ
            if (ioctl(fileno(stdout),TIOCGWINSZ,&screen_size) == -1 ||
                screen_size.ws_col == 0 ||
                screen_size.ws_row == 0) {
#endif
                screen_size.ws_row = 24;
                screen_size.ws_col = 80;
#ifdef TIOCGWINSZ
            }
#endif
            pagerenv=getenv("PAGER");
            if (pagerenv != NULL &&
                pagerenv[0] != '\0' && 
                !po->html3 &&
                ((po->expanded &&
                  nTups * (nFields+1) >= screen_size.ws_row) ||
                 (!po->expanded &&
                  nTups * (total_line_length / screen_size.ws_col + 1) *
                  ( 1 + (po->standard != 0)) >=
                  screen_size.ws_row -
                  (po->header != 0) *
                  (total_line_length / screen_size.ws_col + 1) * 2
                  - (po->header != 0) *2 /* row count and newline */
                  ))) {
                fout = popen(pagerenv, "w");
                if (fout) {
                    usePipe = 1;
                    pqsignal(SIGPIPE, SIG_IGN);
                } else
                  fout = stdout;
            }
        }
        
        if (!po->expanded && (po->align || po->html3)) {
            if (!(fields=(char **)calloc(nFields*(nTups+1), sizeof(char *)))) {
                perror("calloc");
                exit(1);
            }
        } else
          if (po->header && !po->html3) {
              if (po->expanded) {
                  if (po->align)
                    fprintf(fout, "%-*s%s Value\n", 
                            fieldMaxLen-fs_len, "Field", po->fieldSep);
                  else
                    fprintf(fout, "%s%sValue\n", "Field", po->fieldSep);
              } else {
                  int len=0;
                  for (j=0; j < nFields; j++) {
                      char *s=fieldNames[j];
                      fputs(s, fout);
                      len+=strlen(s)+fs_len;
                      if ((j+1)<nFields)
                        fputs(po->fieldSep, fout);
                  }
                  fputc('\n', fout);
                  for (len-=fs_len; len--; fputc('-', fout));
                  fputc('\n', fout);
              }
          }
        if (po->expanded && po->html3) {
            if (po->caption)
              fprintf(fout, "<centre><h2>%s</h2></centre>\n", po->caption);
            else
              fprintf(fout, 
                      "<centre><h2>"
                      "Query retrieved %d rows * %d fields"
                      "</h2></centre>\n", 
                      nTups, nFields);
        }
        for (i = 0; i < nTups; i++) {
            if (po->expanded) {
                if (po->html3)
                  fprintf(fout, 
                          "<table %s><caption align=high>%d</caption>\n", 
                          po->tableOpt? po->tableOpt: "", i);
                else
                  fprintf(fout, "-- RECORD %d --\n", i);
            }
            for (j = 0; j < nFields; j++)
              do_field(po, res, i, j, buf, fs_len, fields, nFields,
                       fieldNames, fieldNotNum,
                       fieldMax, fieldMaxLen, fout);
            if (po->html3 && po->expanded)
              fputs("</table>\n", fout);
        }
        if (!po->expanded && (po->align || po->html3)) {
            if (po->html3) {
                if (po->header) {
                    if (po->caption)
                      fprintf(fout, 
                              "<table %s><caption align=high>%s</caption>\n", 
                              po->tableOpt? po->tableOpt: "", 
                              po->caption);
                    else
                      fprintf(fout, 
                              "<table %s><caption align=high>"
                              "Retrieved %d rows * %d fields"
                              "</caption>\n", 
                              po->tableOpt? po->tableOpt: "", nTups, nFields);
                } else
                  fprintf(fout, "<table %s>", po->tableOpt? po->tableOpt: "");
            }
            if (po->header) 
              do_header(fout, po, nFields, fieldMax, fieldNames, fieldNotNum,
                        fs_len, border, res);
            for (i = 0; i < nTups; i++) 
                output_row(fout, po, nFields, fields, 
                           fieldNotNum, fieldMax, border, i);
            free(fields);
        }
        if (po->header && !po->html3)
          fprintf (fout, "(%d row%s)\n\n",PQntuples(res),
                   (PQntuples(res) == 1) ? "" : "s");
        free(fieldMax);
        free(fieldNotNum);
        free(fieldNames);
        if (usePipe) {
            pclose(fout);
            pqsignal(SIGPIPE, SIG_DFL);
        }
        if (border)
          free(border);
        if (po->html3 && !po->expanded)
          fputs("</table>\n", fout);
    }
}


/* ----------------
 *      PQfn -  Send a function call to the POSTGRES backend.
 *
 *      conn            : backend connection
 *      fnid            : function id
 *      result_buf      : pointer to result buffer (&int if integer)
 *      result_len      : length of return value.
 *      actual_result_len: actual length returned. (differs from result_len
 *                        for varlena structures.)
 *      result_type     : If the result is an integer, this must be 1,
 *                        otherwise this should be 0
 *      args            : pointer to a NULL terminated arg array.
 *                        (length, if integer, and result-pointer)
 *      nargs           : # of arguments in args array.
 *
 * RETURNS
 *      NULL on failure.  PQerrormsg will be set.
 *      "G" if there is a return value.
 *      "V" if there is no return value.
 * ----------------
 */

PGresult*
PQfn(PGconn *conn,
     int fnid,
     int *result_buf,
     int *actual_result_len,
     int result_is_int,
     PQArgBlock *args,
     int nargs)
{
    FILE *pfin, *pfout, *pfdebug;
    int id;
    int i;

    if (!conn) return NULL;

    pfin = conn->Pfin;
    pfout = conn->Pfout;
    pfdebug = conn->Pfdebug;

    /* clear the error string */
    conn->errorMessage[0] = '\0';

    pqPuts("F ",pfout,pfdebug);           /* function */
    pqPutInt(fnid, 4, pfout, pfdebug);    /* function id */
    pqPutInt(nargs, 4, pfout, pfdebug);      /* # of args */

    for (i = 0; i < nargs; ++i) { /*    len.int4 + contents     */
        pqPutInt(args[i].len, 4, pfout, pfdebug);
        if (args[i].isint) {
            pqPutInt(args[i].u.integer, 4, pfout, pfdebug);
        } else {
            pqPutnchar((char *)args[i].u.ptr, args[i].len, pfout, pfdebug);
        }
    }
    pqFlush(pfout, pfdebug);

    id = pqGetc(pfin, pfdebug);
    if (id != 'V') {
        if (id == 'E') {
            pqGets(conn->errorMessage,ERROR_MSG_LENGTH,pfin,pfdebug);
        } else
            sprintf(conn->errorMessage,
                    "PQfn: expected a 'V' from the backend. Got '%c' instead",
                    id);
        return makeEmptyPGresult(conn,PGRES_FATAL_ERROR);
    }

    id = pqGetc(pfin, pfdebug);
    for (;;) {
        int c;
        switch (id) {
        case 'G':               /* function returned properly */
            pqGetInt(actual_result_len,4,pfin,pfdebug);
            if (result_is_int) {
                pqGetInt(result_buf,4,pfin,pfdebug);
            } else {
                pqGetnchar((char *) result_buf, *actual_result_len,
                           pfin, pfdebug);
            }
            c = pqGetc(pfin, pfdebug); /* get the last '0'*/
            return makeEmptyPGresult(conn,PGRES_COMMAND_OK);
        case 'E':
            sprintf(conn->errorMessage,
                    "PQfn: returned an error");
            return makeEmptyPGresult(conn,PGRES_FATAL_ERROR);
        case 'N':
            /* print notice and go back to processing return values */
            if (pqGets(conn->errorMessage, ERROR_MSG_LENGTH, pfin, pfdebug) 
                == 1) {
                sprintf(conn->errorMessage,
                        "Notice return detected from backend, but message "
                        "cannot be read");
            }   else
                fprintf(stderr, "%s\n", conn->errorMessage);
            /* keep iterating */
            break;
        case '0':               /* no return value */
            return makeEmptyPGresult(conn,PGRES_COMMAND_OK);
        default:
            /* The backend violates the protocol. */
            sprintf(conn->errorMessage,
                    "FATAL: PQfn: protocol error: id=%x\n", id);
            return makeEmptyPGresult(conn,PGRES_FATAL_ERROR);
        }
    }
}

/* ====== accessor funcs for PGresult ======== */

ExecStatusType 
PQresultStatus(PGresult* res)
{ 
    if (!res) {
      fprintf(stderr, "PQresultStatus() -- pointer to PQresult is null");
      return PGRES_NONFATAL_ERROR;
    }

    return res->resultStatus; 
}

int 
PQntuples(PGresult *res) 
{
    if (!res) {
      fprintf(stderr, "PQntuples() -- pointer to PQresult is null");
      return (int)NULL;
    }
    return res->ntups;
}

int
PQnfields(PGresult *res) 
{
    if (!res) {
      fprintf(stderr, "PQnfields() -- pointer to PQresult is null");
      return (int)NULL;
    }
    return res->numAttributes;
}

/*
   returns NULL if the field_num is invalid
*/
char* 
PQfname(PGresult *res, int field_num) 
{
    if (!res) {
      fprintf(stderr, "PQfname() -- pointer to PQresult is null");
      return NULL;
    }

    if (field_num > (res->numAttributes - 1))  {
        fprintf(stderr,
                "PQfname: ERROR! name of field %d(of %d) is not available", 
                field_num, res->numAttributes -1);
        return NULL;
    }
    if (res->attDescs) {
        return res->attDescs[field_num].name;
    } else
        return NULL;
}

/*
   returns -1 on a bad field name
*/
int
PQfnumber(PGresult *res, const char* field_name) 
{
  int i;

  if (!res) {
    fprintf(stderr, "PQfnumber() -- pointer to PQresult is null");
    return -1;
  }

  if (field_name == NULL ||
      field_name[0] == '\0' ||
      res->attDescs == NULL)
    return  -1;

  for (i=0;i<res->numAttributes;i++) {
    if ( strcmp(field_name, res->attDescs[i].name) == 0 )
      return i;
  }
  return -1;

}

Oid
PQftype(PGresult *res, int field_num) 
{
    if (!res) {
      fprintf(stderr, "PQftype() -- pointer to PQresult is null");
      return InvalidOid;
    }

    if (field_num > (res->numAttributes - 1))  {
        fprintf(stderr,
                "PQftype: ERROR! type of field %d(of %d) is not available", 
                field_num, res->numAttributes -1);
    }
    if (res->attDescs) {
        return res->attDescs[field_num].adtid;
    } else
        return InvalidOid;
}

int2
PQfsize(PGresult *res, int field_num) 
{
    if (!res) {
      fprintf(stderr, "PQfsize() -- pointer to PQresult is null");
      return (int2)NULL;
    }

    if (field_num > (res->numAttributes - 1))  {
        fprintf(stderr,
                "PQfsize: ERROR! size of field %d(of %d) is not available", 
                field_num, res->numAttributes -1);
    }
    if (res->attDescs) {
        return res->attDescs[field_num].adtsize;
    } else
        return 0;
}

char* PQcmdStatus(PGresult *res) {
  if (!res) {
    fprintf(stderr, "PQcmdStatus() -- pointer to PQresult is null");
    return NULL;
  }
  return res->cmdStatus;
}

/*
   PQoidStatus -
    if the last command was an INSERT, return the oid string 
    if not, return ""
*/
const char* PQoidStatus(PGresult *res) {
  if (!res) {
    fprintf(stderr, "PQoidStatus() -- pointer to PQresult is null");
    return NULL;
  }

  if (!res->cmdStatus)
    return "";

  if (strncmp(res->cmdStatus, "INSERT",6) == 0) {
    return res->cmdStatus+7;
  } else
    return "";
}

/*
   PQgetvalue:
    return the value of field 'field_num' of row 'tup_num'

    If res is binary, then the value returned is NOT a null-terminated 
    ASCII string, but the binary representation in the server's native
    format.

    if res is not binary, a null-terminated ASCII string is returned.
*/
char* 
PQgetvalue(PGresult *res, int tup_num, int field_num)
{
    if (!res) {
      fprintf(stderr, "PQgetvalue: pointer to PQresult is null\n");
      return NULL;
    } else if (tup_num > (res->ntups - 1)) {
      fprintf(stderr, 
              "PQgetvalue: There is no row %d in the query results.  "
              "The highest numbered row is %d.\n",
              tup_num, res->ntups - 1);
      return NULL;
    } else if (field_num > (res->numAttributes - 1)) {
      fprintf(stderr,
              "PQgetvalue: There is no field %d in the query results.  "
              "The highest numbered field is %d.\n", 
              field_num, res->numAttributes - 1);
      return NULL;
    }
    
    return res->tuples[tup_num][field_num].value;
}



/* PQgetlength:
     returns the length of a field value in bytes.  If res is binary,
     i.e. a result of a binary portal, then the length returned does
     NOT include the size field of the varlena.
*/
int
PQgetlength(PGresult *res, int tup_num, int field_num)
{
    if (!res) {
      fprintf(stderr, "PQgetlength() -- pointer to PQresult is null");
        return (int)NULL;
    }

    if (tup_num > (res->ntups - 1 )||
        field_num > (res->numAttributes - 1))  {
        fprintf(stderr,
                "PQgetlength: ERROR! field %d(of %d) of row %d(of %d) "
                "is not available", 
                field_num, res->numAttributes - 1, tup_num, res->ntups);
    }

    if (res->tuples[tup_num][field_num].len != NULL_LEN)
        return res->tuples[tup_num][field_num].len;
    else
        return 0;
  }

/* PQgetisnull:
     returns the null status of a field value.
*/
int
PQgetisnull(PGresult *res, int tup_num, int field_num)
{
    if (!res) {
      fprintf(stderr, "PQgetisnull() -- pointer to PQresult is null");
        return (int)NULL;
    }

    if (tup_num > (res->ntups - 1 )||
        field_num > (res->numAttributes - 1))  {
        fprintf(stderr,
                "PQgetisnull: ERROR! field %d(of %d) of row %d(of %d) "
                "is not available", 
                field_num, res->numAttributes - 1, tup_num, res->ntups);
    }

    if (res->tuples[tup_num][field_num].len == NULL_LEN)
        return 1;
    else
        return 0;
  }
